Breaking

Stem Cell Transplants Clear HIV in Two Patients in Study

A researcher applies supplement to stem cells in a lab at the Gladstone Institute of Cardiovascular Disease in San Francisco. Photographer: Noah Berger/Bloomberg

July 3 (Bloomberg) -- Two cancer patients in Boston who
were also infected with HIV have no trace of the virus after
receiving stem-cell transplants, suggesting they may have been
cured of the AIDS-causing infection.

The two patients, treated at Brigham and Women’s Hospital,
stopped HIV treatment after the transplants, which in other
patients has opened the door for the virus to come roaring back.
In one patient there was no sign of the virus 15 weeks after
stopping treatment, while the other has gone seven weeks without
HIV rebounding, according to results presented today at the
International AIDS Society’s meeting in Kuala Lumpur.

The researchers led by Timothy Henrich of Harvard Medical
School and Brigham and Women’s Hospital said it’s too early to
conclude the two men have been cured and the virus may be
lingering in their brains or gut. Still, their cases are similar
to that of Timothy Brown, the so-called Berlin patient, who was
the first person to be cured of HIV after getting a bone marrow
transplant for leukemia in 2007.

“While stem-cell transplantation is not a viable option
for people with HIV on a broad scale because of its costs and
complexity, these new cases could lead us to new approaches to
treating, and ultimately even eradicating, HIV,” Kevin Robert
Frost, the chief executive officer of amfAR, The Foundation for
AIDS Research, which funded the study, said in a statement.

Gene Mutation

There was one main difference between Brown and the two
Boston men: the cells he received contained a rare genetic
mutation called CCR5 that made him resistant to HIV infection.
The donors in the new cases lacked that mutation, and the Boston
patients didn’t undergo the intensive chemotherapy Brown did.

Scientists had believed the CCR5 mutation was key to Brown
being cured. They’ll be searching through the new results for
clues to whether other genes may hold promise against HIV,
Rowena Johnston, amfAR’s director of research, said in an e-mail.

“This stuff is really very exciting scientifically, and it
really captures the imagination of the patients,” said Paul E.
Sax, a professor of medicine at Harvard Medical School and a
clinician at Brigham and Women’s. “All of us get asked by our
patients about these cases, even to the point of people actually
requesting bone marrow transplants.”

Drug Cocktails

While AIDS drugs such as Gilead Sciences Inc.’s Atripla
reduce HIV to undetectable levels in the body, making it a
chronic disease, they don’t completely clear it. The virus hides
in certain immune cells, where it switches off the normal
process of replication. That enables HIV to avoid detection by
the medicines, which are designed to block steps in its
reproduction.

Studies have shown that when patients who have the virus
under control stop treatment, latent HIV reactivates and comes
roaring back, forcing victims to resume daily pill therapy.

Doctors in March said they had cured an infant born with
HIV for the first time by treating her with AIDS drugs about 30
hours after she was born at a rural Mississippi hospital. At 18
months the mother took the child off medication, and when the
virus had not returned 10 months later, she was deemed
“functionally cured.”